1. Field of the Invention
This invention relates generally to phased array antennas and more particularly to a phased array antenna that provides simultaneous dual polarization operation.
2. Description of Related Art
There are applications that require a low cost phased array antenna that provides simultaneous dual polarization operation. This requires the antenna to have radiators that can radiate either vertical or horizontal polarization. Accordingly, there must be two separate combining manifolds. These requirements place a burden on available packaging space, particularly for antennas operating in the millimeter wave frequency range or higher.
It is an object of the present invention, therefore, to provide an improvement in phased array antennas.
It is a further object of the invention to provide a dual polarized single axis phased array antenna which is operable in the millimeter wave range of RF frequencies.
It is still another object of the invention to provide a simultaneous dual polarized phase array antenna which electrically scans a beam in azimuth while generating a fixed beam in elevation.
These and other objects are achieved by a dual polarized single axis scanned phased array antenna comprising a plurality of mutually adjacent radiating columns which generate respective beams scannable in azimuth while providing a fixed beam in elevation, and wherein each radiating column utilizes a low loss dielectric slab assembly to serve multiple functions. The slab assembly serves, among other things, as a lens to correct the spherical wave from a small feed to a plain wave within a column. The slab assembly also includes a septum polarizer necessary to carry both horizontally and vertically polarized fields. The slab assembly additionally includes a dielectric radiator element to provide a radiating surface without the need to form a ground plane. The dielectric slab assembly, moreover, inherently loads the radiating columns so that they can be spaced one half of a free space wavelength without cutting off the vertically polarized fields.
Further scope of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood, however, that the detailed description and specific example, while disclosing the preferred embodiment of the invention, it is provided by way of illustration only, since various changes and modifications coming within the spirit and scope of the invention will become apparent to those skilled in the art from the following detailed description.